glgE Resolved · high auto-curated
H37Rv Rv1327c · MTBC0 - ·
701 aa · 1492320–1494425 (-) ·
RefSeq NP_215843.2
Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase |
|---|---|
| MTBC0 PGAP re-annotation | — |
| Revised (this work) | Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase. Pfam: GlgE_dom_N_S (PF11896.15), GLGE_C (PF21702.4). |
Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.
Annotated on the H37Rv protein: this gene has no 1:1 ancestral MTBC0 anchor (PE/PPE, paralogue, IS element, or otherwise unanchored CDS).
Curated reference (UniProt)
| UniProt |
P9WQ17
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase |
| EC (curated) |
EC 2.4.99.16
|
| Curated function | Essential maltosyltransferase that uses maltose 1-phosphate (M1P) as the sugar donor to elongate linear or branched alpha-(1->4)-glucans. Maltooligosaccharides with a degree of polymerization (DP) superior or equal to 4 are efficient acceptors, with DP5 being optimal in the GlgE-catalyzed polymerization with M1P. Is specific for the alpha-anomer of M1P as substrate, since the beta-anomer of M1P gives no activity. Exhibits an alpha-retaining catalytic mechanism. Is also able to catalyze the reverse reaction in vitro, releasing M1P from glycogen in the presence of inorganic phosphate. Also catal. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
G Carbohydrate transport and metabolism
|
|---|---|
| Preferred name | glgE |
| eggNOG description | Maltosyltransferase that uses maltose 1-phosphate (M1P) as the sugar donor to elongate linear or branched alpha-(1- 4)- glucans. Is involved in a branched alpha-glucan biosynthetic pathway from trehalose, together with TreS, Mak and GlgB |
| Orthologous group | COG0366 |
| EC number |
EC 2.4.99.16
|
| KEGG orthology |
K16147
|
| KEGG pathways |
map00500, map01100
|
| CAZy family |
GH13
|
| Gene Ontology (18) |
GO:0003674, GO:0003824, GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0008150, GO:0016020, GO:0016740, GO:0016757 +6 more
|
Orthology-based transfer (eggNOG 5.0.2, diamond). EC/KO/GO/CAZy are computed annotations, not manual curation; cross-check against the primary literature before treating a specific reaction as established.
Conservation & selection (intra-MTBC, 145 209 strains)
| pN/pS | 0.566 · relaxed/neutral |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 4 synonymous, 7 missense, 0 nonsense, 0 frameshift |
pN/pS from segregating SNPs (singletons removed) normalised by possible sites. Low pN/pS = purifying selection (a strong signal that a "hypothetical" is a real, constrained gene). A high pN/pS is ambiguous: relaxed constraint or positive selection (drug resistance, antigenic variation) inflate it; e.g. rpoB/katG/pncA score high here for resistance, not loss of function. A clonal disruption (one allele over a clade) suggests lineage pseudogenisation; a convergent one (many independent alleles) is typical of resistance loss-of-function.
Domains (Pfam, hmmscan --cut_ga)
| Pfam | Accession | i-Evalue | Residues | Description |
|---|---|---|---|---|
GlgE_dom_N_S | PF11896.15 | 4.2e-53 | 16–226 | Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase, domain N/S |
GLGE_C | PF21702.4 | 2.1e-32 | 600–685 | GLGE, C-terminal |
Functional interaction network (STRING v12, guilt-by-association)
Closest characterised functional partner: glgB (1,4-alpha-glucan branching protein), high confidence from genomic context alone (score 999 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv1326c glgB |
1,4-alpha-glucan branching protein | 999 | 999 ctx | neighborhood:882 coexpression:844 database:900 textmining:965 |
Rv0127 mak |
maltokinase | 999 | 990 ctx | cooccurence:771 experimental:484 database:900 textmining:965 |
Rv1212c glgA |
capsular glucan synthase | 998 | 970 ctx | cooccurence:662 database:900 textmining:959 |
Rv1781c malQ |
4-alpha-glucanotransferase | 980 | 951 | database:900 textmining:610 |
Rv3032 |
glycogen synthase | 984 | 914 | database:900 textmining:829 |
Rv3031 |
1,4-alpha-glucan-branching protein | 981 | 901 | database:900 textmining:824 |
Rv1328 glgP |
glycogen phosphorylase | 990 | 858 ctx | neighborhood:772 textmining:936 |
Rv1564c treX |
maltooligosyl trehalose synthase | 965 | 820 ctx | cooccurence:650 coexpression:425 textmining:815 |
Rv1562c treZ |
malto-oligosyltrehalose trehalohydrolase | 990 | 814 ctx | cooccurence:728 textmining:949 |
Rv1563c treY |
maltooligosyl trehalose synthase | 983 | 802 ctx | cooccurence:745 textmining:921 |
Rv0126 treS |
trehalose synthase/amylase TreS | 988 | 788 ctx | cooccurence:751 textmining:949 |
Rv3253c |
cationic amino acid transport integral membrane protein | 775 | 764 | experimental:451 database:577 |
Rv2690c |
integral membrane protein | 775 | 764 | experimental:451 database:577 |
Rv1999c |
transporter | 775 | 764 | experimental:451 database:577 |
Rv2320c rocE |
cationic amino acid transporter permease RocE | 775 | 764 | experimental:451 database:577 |
STRING combines evidence channels (neighborhood, fusion, cooccurrence, coexpression, experimental, database, text-mining) into a 0–1000 score. The ctx badge marks edges carried by the genomic-context channels (conserved neighborhood, fusion, phylogenetic co-occurrence), which are independent of orthology and structure and the strongest signal for an unknown gene. The no text-mining column recomputes the score from data alone, so a link that does not depend on the literature is visible. Association is a function hypothesis, not proof: corroborate with the operon context and the primary literature before assigning a function.
Evidence
- Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase
- Pfam (hmmscan --cut_ga): GlgE_dom_N_S PF11896.15 (E=4e-53), GLGE_C PF21702.4 (E=2e-32)
- (auto-curated by rules from PGAP + Pfam + Foldseek; not hand-reviewed)
Sources
- Ancestral sequence & coordinates: Harrison LB et al. (2024), An imputed ancestral reference genome for the MTBC, doi:10.1101/2023.09.07.556366
- Product annotation: NCBI PGAP on MTBC0; legacy from H37Rv NC_000962.3 (RefSeq NP_215843.2)
- Domains: Pfam-A via hmmscan --cut_ga — GlgE_dom_N_S (PF11896.15), GLGE_C (PF21702.4)
- Sequence-level signal: ESM Atlas (EvolutionaryScale × BioHub) — exploratory
- Controlled vocabulary: eggNOG-mapper 2.1.12 (Cantalapiedra et al. 2021,
doi:10.1093/molbev/msab293), eggNOG 5.0 DB
(Huerta-Cepas et al. 2019) — OG
COG0366 - Curated reference: UniProt P9WQ17 (SwissProt, reviewed; Evidence at protein level)
- Intra-MTBC selection: pN/pS and disruption from SPDI variants of 145 209 MTBC strains (this work, local collection vs H37Rv NC_000962.3)
- Interaction network: STRING v12.0 (Szklarczyk et al. 2023,
doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 —
41 functional partner(s); context anchor
glgB - Primary literature: none located yet; annotation rests on the domain/homology sources above.
Ancestral MTBC0 protein sequence
>H37Rv|Rv1327c|glgE MSGRAIGTETEWWVPGRVEIDDVAPVVSCGVYPAKAVVGEVVPVSAAVWREGHEAVAATLVVRYLGVRYPHLTDRPRARVLPTPSEPQQRVKPLLIPMTSGQEPFVFHGQFTPDRVGLWTFRVDGWGDPIHTWRHGLIAKLDAGQGETELSNDLLVGAVLLERAATGVPRGLRDPLLAAAAALRTPGDPVTRTALALTPEIEELLADYPLRDLVTRGEQFGVWVDRPLARFGAWYEMFPRSTGGWDDDGNPVHGTFATAAAELPRIAGMGFDVVYLPPIHPIGKVHRKGRNNSPTAAPTDVGSPWAIGSDEGGHDTVHPSLGTIDDFDDFVSAARDLGMEVALDLALQCAPDHPWAREHRQWFTELPDGTIAYAENPPKKYQDIYPLNFDNDPEGLYDEVLRVVQHWVNHGVKFFRVDNPHTKPPNFWAWLIAQVKTVDPDVLFLSEAFTPPARQYGLAKLGFTQSYSYFTWRTTKWELTEFGNQIAELADYRRPNLFVNTPDILHAVLQHNGPGMFAIRAVLAATMSPAWGMYCGYELFEHRAVREGSEEYLDSEKYELRPRDFASALDQGRSLQPFITRLNIIRRLHPAFQQLRTIHFHHVDNDALLAYSKFDPATGDCVLVVVTLNAFGPEEATLWLDMAALGMEDYDRFWVRDEITGEEYQWGQANYIRIDPARAVAHIINMPAVPYESRNTLLRRR